{"cve":"CVE-2021-30479","nvd":{"published":"2021-04-15T00:15:13.170","modified":"2026-06-17T03:50:19.083","status":"Modified","description":"An issue was discovered in Zulip Server before 3.4. A bug in the implementation of the all_public_streams API feature resulted in guest users being able to receive message traffic to public streams that should have been only accessible to members of the organization.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N","score":5.3},"cwes":["CWE-269"],"references":["https://blog.zulip.com/2021/04/14/zulip-server-3-4/","https://blog.zulip.com/2021/04/14/zulip-server-3-4/"],"products":["zulip:zulip_server"],"source":"nvd","synced_at":"2026-10-19T21:17:01.373894544+00:00"},"epss":{"cve":"CVE-2021-30479","score":0.00862,"percentile":0.58593,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}